/***
 * ASM: a very small and fast Java bytecode manipulation framework
 * Copyright (c) 2000-2011 INRIA, France Telecom
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the copyright holders nor the names of its
 *    contributors may be used to endorse or promote products derived from
 *    this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
 * THE POSSIBILITY OF SUCH DAMAGE.
 */
package org.objectweb.asm.tree;

import java.util.ArrayList;
import java.util.List;
import java.util.Map;

import org.objectweb.asm.MethodVisitor;

/**
 * A node that represents a bytecode instruction. <i>An instruction can appear
 * at most once in at most one {@link InsnList} at a time</i>.
 * 
 * @author Eric Bruneton
 */
public abstract class AbstractInsnNode {

  /**
   * The type of {@link InsnNode} instructions.
   */
  public static final int INSN = 0;

  /**
   * The type of {@link IntInsnNode} instructions.
   */
  public static final int INT_INSN = 1;

  /**
   * The type of {@link VarInsnNode} instructions.
   */
  public static final int VAR_INSN = 2;

  /**
   * The type of {@link TypeInsnNode} instructions.
   */
  public static final int TYPE_INSN = 3;

  /**
   * The type of {@link FieldInsnNode} instructions.
   */
  public static final int FIELD_INSN = 4;

  /**
   * The type of {@link MethodInsnNode} instructions.
   */
  public static final int METHOD_INSN = 5;

  /**
   * The type of {@link InvokeDynamicInsnNode} instructions.
   */
  public static final int INVOKE_DYNAMIC_INSN = 6;

  /**
   * The type of {@link JumpInsnNode} instructions.
   */
  public static final int JUMP_INSN = 7;

  /**
   * The type of {@link LabelNode} "instructions".
   */
  public static final int LABEL = 8;

  /**
   * The type of {@link LdcInsnNode} instructions.
   */
  public static final int LDC_INSN = 9;

  /**
   * The type of {@link IincInsnNode} instructions.
   */
  public static final int IINC_INSN = 10;

  /**
   * The type of {@link TableSwitchInsnNode} instructions.
   */
  public static final int TABLESWITCH_INSN = 11;

  /**
   * The type of {@link LookupSwitchInsnNode} instructions.
   */
  public static final int LOOKUPSWITCH_INSN = 12;

  /**
   * The type of {@link MultiANewArrayInsnNode} instructions.
   */
  public static final int MULTIANEWARRAY_INSN = 13;

  /**
   * The type of {@link FrameNode} "instructions".
   */
  public static final int FRAME = 14;

  /**
   * The type of {@link LineNumberNode} "instructions".
   */
  public static final int LINE = 15;

  /**
   * The opcode of this instruction.
   */
  protected int opcode;

  /**
   * The runtime visible type annotations of this instruction. This field is
   * only used for real instructions (i.e. not for labels, frames, or line
   * number nodes). This list is a list of {@link TypeAnnotationNode} objects.
   * May be <tt>null</tt>.
   * 
   * @associates org.objectweb.asm.tree.TypeAnnotationNode
   * @label visible
   */
  public List<TypeAnnotationNode> visibleTypeAnnotations;

  /**
   * The runtime invisible type annotations of this instruction. This field is
   * only used for real instructions (i.e. not for labels, frames, or line
   * number nodes). This list is a list of {@link TypeAnnotationNode} objects.
   * May be <tt>null</tt>.
   * 
   * @associates org.objectweb.asm.tree.TypeAnnotationNode
   * @label invisible
   */
  public List<TypeAnnotationNode> invisibleTypeAnnotations;

  /**
   * Previous instruction in the list to which this instruction belongs.
   */
  AbstractInsnNode prev;

  /**
   * Next instruction in the list to which this instruction belongs.
   */
  AbstractInsnNode next;

  /**
   * Index of this instruction in the list to which it belongs. The value of
   * this field is correct only when {@link InsnList#cache} is not null. A value
   * of -1 indicates that this instruction does not belong to any
   * {@link InsnList}.
   */
  int index;

  /**
   * Constructs a new {@link AbstractInsnNode}.
   * 
   * @param opcode
   *          the opcode of the instruction to be constructed.
   */
  protected AbstractInsnNode(final int opcode) {
    this.opcode = opcode;
    this.index = -1;
  }

  /**
   * Returns the opcode of this instruction.
   * 
   * @return the opcode of this instruction.
   */
  public int getOpcode() {
    return opcode;
  }

  /**
   * Returns the type of this instruction.
   * 
   * @return the type of this instruction, i.e. one the constants defined in
   *         this class.
   */
  public abstract int getType();

  /**
   * Returns the previous instruction in the list to which this instruction
   * belongs, if any.
   * 
   * @return the previous instruction in the list to which this instruction
   *         belongs, if any. May be <tt>null</tt>.
   */
  public AbstractInsnNode getPrevious() {
    return prev;
  }

  /**
   * Returns the next instruction in the list to which this instruction belongs,
   * if any.
   * 
   * @return the next instruction in the list to which this instruction belongs,
   *         if any. May be <tt>null</tt>.
   */
  public AbstractInsnNode getNext() {
    return next;
  }

  /**
   * Makes the given code visitor visit this instruction.
   * 
   * @param cv
   *          a code visitor.
   */
  public abstract void accept(final MethodVisitor cv);

  /**
   * Makes the given visitor visit the annotations of this instruction.
   * 
   * @param mv
   *          a method visitor.
   */
  protected final void acceptAnnotations(final MethodVisitor mv) {
    int n = visibleTypeAnnotations == null ? 0 : visibleTypeAnnotations.size();
    for (int i = 0; i < n; ++i) {
      TypeAnnotationNode an = visibleTypeAnnotations.get(i);
      an.accept(mv.visitInsnAnnotation(an.typeRef, an.typePath, an.desc, true));
    }
    n = invisibleTypeAnnotations == null ? 0 : invisibleTypeAnnotations.size();
    for (int i = 0; i < n; ++i) {
      TypeAnnotationNode an = invisibleTypeAnnotations.get(i);
      an.accept(mv.visitInsnAnnotation(an.typeRef, an.typePath, an.desc, false));
    }
  }

  /**
   * Returns a copy of this instruction.
   * 
   * @param labels
   *          a map from LabelNodes to cloned LabelNodes.
   * @return a copy of this instruction. The returned instruction does not
   *         belong to any {@link InsnList}.
   */
  public abstract AbstractInsnNode clone(final Map<LabelNode, LabelNode> labels);

  /**
   * Returns the clone of the given label.
   * 
   * @param label
   *          a label.
   * @param map
   *          a map from LabelNodes to cloned LabelNodes.
   * @return the clone of the given label.
   */
  static LabelNode clone(final LabelNode label, final Map<LabelNode, LabelNode> map) {
    return map.get(label);
  }

  /**
   * Returns the clones of the given labels.
   * 
   * @param labels
   *          a list of labels.
   * @param map
   *          a map from LabelNodes to cloned LabelNodes.
   * @return the clones of the given labels.
   */
  static LabelNode[] clone(final List<LabelNode> labels, final Map<LabelNode, LabelNode> map) {
    LabelNode[] clones = new LabelNode[labels.size()];
    for (int i = 0; i < clones.length; ++i) {
      clones[i] = map.get(labels.get(i));
    }
    return clones;
  }

  /**
   * Clones the annotations of the given instruction into this instruction.
   * 
   * @param insn
   *          the source instruction.
   * @return this instruction.
   */
  protected final AbstractInsnNode cloneAnnotations(final AbstractInsnNode insn) {
    if (insn.visibleTypeAnnotations != null) {
      this.visibleTypeAnnotations = new ArrayList<TypeAnnotationNode>();
      for (int i = 0; i < insn.visibleTypeAnnotations.size(); ++i) {
        TypeAnnotationNode src = insn.visibleTypeAnnotations.get(i);
        TypeAnnotationNode ann = new TypeAnnotationNode(src.typeRef, src.typePath, src.desc);
        src.accept(ann);
        this.visibleTypeAnnotations.add(ann);
      }
    }
    if (insn.invisibleTypeAnnotations != null) {
      this.invisibleTypeAnnotations = new ArrayList<TypeAnnotationNode>();
      for (int i = 0; i < insn.invisibleTypeAnnotations.size(); ++i) {
        TypeAnnotationNode src = insn.invisibleTypeAnnotations.get(i);
        TypeAnnotationNode ann = new TypeAnnotationNode(src.typeRef, src.typePath, src.desc);
        src.accept(ann);
        this.invisibleTypeAnnotations.add(ann);
      }
    }
    return this;
  }

  public void setOpcode(int opcodeIndex) {
    this.opcode = opcodeIndex;
  }
}
